Grate structure



'.J. w. HULsoN March 3l, 1 942.

@RATE STRUCTURE Filed July 3o, 1940 wmves J. w. HULSON GRATE STRUCTUREFiled July 30, 1940 March 31, 1.942.

2 Sheets-Sheet 2 JOM lmf. Huw/sn 'onere sran f Y .lohn W. Hudson,Keoimlx, Iowa, assigner to iiulson Grate Gompany, Keokuh, iowayimplication July 30, 1940, Serial No. 348,473

i Claim.

The invention relates to a locomotive grate structure of the generaltype disclosed in my U. S.

4Patent No. 2,009,450 of July 30, 1935, in which various grate sectionswere formed of fingers as-4 ,of rigging fire box, and this condition wasaggravated with wear of trunnions, pivots, etc. Such Causing one end ofthe fingers of grate section to rise and the other end of iingers of thenext grate section to lower,y crestraight-draft openings through whichsome ofthe draft air could pass through the grate withoutbeing subjectedto .the bailling action of the tuyeres. While these straight-draftopenings were not objectionable in the era ln which the aforesaid patentissued,'they later caused a great deal of trouble and fuel loss whenlocomotive speeds and loads were increased and ne fuels, oftenscreenings of very light sub-bitumi nous coal, were used. Under theseconditions, quite an amount of fuel was lost to the ash pit i rough theaforesaid straight-draft openings when standing by, and similar'lossoften occurred when running with light draft. Moreover, when operatingat high speeds and under heavy'loads requiring forcible draft, theunbafhed draft air passing through said straight-draft openings, wouldcarry burning fuel from the grate through the locomotive flues andstack, not only wasting .i'uel but causing slagging of ilues, and cindercutting. The present invention aims to so improve the grate finge-r of'the aforesaid nt as to overcome the above discussed dimand extended useof ylocomotive grates ving the improved ngers, has proven that the edend has Ybeen attained.

with' the 'foregoing ln view, the invention redescribed and claimed,description being accom- 'A preferred construction has been illustratedand will be rather specifically described, with the understanding,however, .that within the scope of the invention as claimed, variationsmay be made. While the description will relate to a structure in whicheach grate section includes separate fingers on a finger bar, it is tobe understood that the improvements are equally applicable to a unitarygrate section.

Each grate 'section in the present disclosure comprises a finger bar II)and a plurality of 1ingers ll mounted thereon, the pivots of the fingerbars being denoted at I2. These finger bars are provided with the usualdownwardly projecting arms I3 which are pivoted to the conventionalshaker rigging it.

Each 'finger lI comprises an enlarged head l5 extending longitudinallyof the upper edge of a vertical web I6, and said head consists of alongitudinal'ridge Il and ribs I8 extending longitudinally of the lowerportion of said ridge. The ridge lll is centrally located andthere aretwo .of the ribs'it projecting laterally from the plis-.hed by referenceto the accompanying drawings.

Figure i is a fragmentary top plan view showing a grate constructed inaccordance with the present invention.

Figure 2 is a vertical longitudinal sectional l view on line 2-2 of Fig.l showing the grate secopposite sides of` said ridge. When a pluralityof the fingers H are assembled in side-to-side contact upon a finger barI0 to form a complete grate section, the ribs I form the bottoms ofairconducting valleys I 9 between the fire-supporting yridges I1. Thevalleys I9 have suitable air inlet openings or tuyres 20 lwhich baffleand diffuse the draught air drawn through. the grate under the infiuenceof the locomotive exhaust, and the fire-supporting ridges Il are formedwith transverse air-conducting channels ZI. Everything so far describedis disclosed in the above mentioned patent. My improvement, however,resides in novel structure including end Walls 22 `for the Valleys I9,said end walls being joined to the ridges II and to the lateral ribs I8.Each end surface of each finger head I5 consists' of an upper half lledisposed substantially in a ltransverse plane inclined in one direction,and a lower half lll disposed substantially in a second transverse planeVinclined in the other direction, said upper and lowerr halvesconverging to a transverse horizontal ridge line 23 at the extreme endof said head I5. The end walls 22 at opposite sides of the ridge Ilextend upwardly from the ribs i8 to the ridge line 23 and the outertransverse sides of these walls form portions of the inclined lower halfI'Ib of the above described end surface of said head I5.

When the grate sections are in cold grate position or otherwise inslightly tilted position as seen in Figs. 2 and 3, a certain distance 25(Fig. 3) exists between the end wall tips 23 at one end of the valleys I9 of any grate section, and the adjacent wall heels 24 of the next gratesection. This space, due to the provision of thev inclined walls 22, isconsiderably less than the shortest distance which would exist betweenthe adjacent ends of the valley bottoms I8, were said Walls 22 notemployed. Thus, with the improved end structures including these walls,there will be less loss of fuel between grate sections when thesesections occupy cold grate position, and as the re is started and a bedof coals forms on the grate, the expansion of the ire box and the shakerrigging il will bring the various grate sections to substantiallyhorizontal position for operation. Also, during operation, should thegrate sections again become slightly tilted, no

straight-draftV openings of objectionable size will be `formed betweenthem and, therefore, the

previous difficulty with respect to stack loss, cinder cutting and flueslagging, will be overcome. The walls 22 do not materially interferewith shaking the ash through the grate nor with dumping the fire andthey provide an increased vertical section at the ends of the ngerswhich will increase the life of the latter in addition to giving theabove describedadvantages.

In Fig. 3, in order to emphasize the extent to which the distance 25 isdecreased over the distance which would exist if the walls 22 were notused, I have placed dotted lines 21 on the view, even with the uppersides of the ribs I8. By considering the walls 22 cut off along thedotted lines 21 and comparing the distance 2B which wouldV then existbetween the fingers of adjacent grate sections with the latter tilted,with the distance 25 which would exist when using the walls tion in thespace between adjacent grate sec tions, when in cold grate or otherslightly tilted position, has been effected, to prevent fuel fromsifting into the ash pit and to prevent stack loss, cinder lcutting andilue-slagging.

While it is to be understood that am not restricted to exact proportionsor dimensions, I have found that excellent results exist when each wall22 extends above the rib i8 a distance substantially equal to thevertical thickness of said rib and when the inclined surface Hb is atsubstantially 120 to the'lower side of the rib 48.

tially in a second rtransverse plane inclined in the other direction,said upper and lower halves converging to a transverse'horizontal ridgeline at the` extreme end of said head, ,said ridge line 'being in aplane above the upper sides oi' said ribs, and transverse end wallsintegrally joined .to vsaid ribs and to the lower portions of thelateral sides of said fire-supporting ridge, said end y walls extendingupwardly from said-ribs to said 22, it may be readily seen that a markedreduc transverse horizontal ridge lines at the extreme ends o! said headandy having outer sides' forining portions of said inclined lower halvesof said end surfaces of said head.

JOHN W. HULSON.

